Coastal Geology

The Coastal Geology group studies the geological evolution of coastal environments, such as beaches, dunes, barrier islands, wetlands, and estuaries. Emphasis is placed on process-based investigations into the dynamics of these environments and how they might evolve in the future with changing conditions. Our research is field-based and aimed at discerning the geomorphology, sedimentology and geologic history of coastal environments. We use these data to parameterize coastal change models as well as to assist coastal managers in decision-making.

Read more about how ISGS scientists are working with the Illinois Department of Natural Resources to develop a better understanding of shoreline dynamics along the Illinois coast of Lake Michigan, including studying shoreline dynamics, erosion, and habitat loss at Illinois Beach State Park, one of the last stretches of natural coastline in Illinois.

Projects

  • Sustainable Nearshore Management Solutions to Prevent Critical Habitat Loss at Illinois Beach State Park: Development of a habitat vulnerability model that takes into account the value of coastal habitat along a beach ridge complex and the short-term and long-term threats to that habitat from natural and anthropogenic coastal processes.

  • Role of lacustrine overwash in geomorphic evolution at a beach ridge complex: Development of a conceptual model of coastal geomorphic evolution in response to lacustrine overwash by coupling in-situ observations of overwash with topographic change data. This model enhances our ability to accurately simulate future coastal response to storms and lake level fluctuations.

  • Quantifying the annual carbon budget from a rapidly eroding freshwater coastal wetland using field and model data: Development of a transect carbon budget model that simulates changes in wetland carbon storage in response to erosion and overwash.

  • Mapping geomorphic change along Great Lakes coastlines with small unmanned aerial systems (s-UAS): s-UAS provide a low-cost and efficient method for mapping coastal erosion and accretion, however, this technique has not been employed frequently in the Great Lakes. This project aims to evaluate the utility of s-UAS for shoreline change mapping in the Great Lakes. Additionally, protocols for long-term coastal monitoring with s-UAS will be developed to aid coastal managers.

  • Coastal geomorphic response to seasonal lake level rise in the Laurentian Great Lakes: Frequent monitoring of topographic change along a beach ridge complex revealed spatial and temporal variability in beach response to seasonal fluctuations in lake level. Areas south of shore protection eroded immediately as lake level rose, while other areas did not erode until the co-occurrence of maximum lake level and an increase in wave energy. This study provided important insight into the system dynamics of a lacustrine coastal processes.

  • High-resolution monitoring of Illinois Lake Michigan waves and currents to improve coastal models and public safety: Deployment of two wave and current buoys along the Illinois coast of Lake Michigan (Waukegan Harbor and Winthrop Harbor, IL) in order to gain insight into the hydrodynamic processes driving coastal geomorphic change and sediment transport. Additionally, a proxy model using land-based data such as time-series imagery and meteorological data will be developed so that an in-situ estimate of wave conditions can be made even when buoys are removed during the winter.

  • Sediment transport associated with nearshore sediment placement: Nearshore placement of dredged material is a common practice in the Great Lakes; however, no studies have evaluated the fate of this material. Monthly nearshore bathymetric mapping and beach topography mapping will provide insight into the transport pathways of this sediment.

  • Evaluating the efficacy of annual beach nourishment at an engineered headland-bay beach: Annual beach nourishment is requisite at many sites in order to maintain recreational use, yet the efficacy of this practice is poorly understood. In particular, few quantitative linkages have been made between erosion of nourished sand and coastal processes, such as storms and lake level rise. This study will monitor erosion and accretion at a nourishment site in response to fluctuating lake level and storm events with the aim of identifying the most important processes to plan for to ensure successful nourishment

  • Littoral sediment transport pathways along Western Lake Michigan: From source to sink: Rates and processes associated with littoral transport along Western Lake Michigan are poorly understood. This study aims to quantify the fate of sand once it is liberated from the bluffs of southeastern Wisconsin. Sedimentologic analyses are coupled with nearshore geophysical surveys to evaluate sources and sinks of nearshore sediments. The ultimate goal of this work is to provide coastal managers with a more realistic assessment of littoral transport along Western Lake Michigan.

  • Decadal and annual changes in nearshore sand thickness and lakebed elevation in Western Lake Michigan: Quantifying changes in sand thickness and lakebed erosion is requisite for modeling coastal evolution. An innovative airborne electromagnetic technique was coupled with vessel-based sub-bottom profiling and bathymetric surveying to quantify recent sand thickness and lakebed elevation. These measurements were compared to past measurements in order to evaluate changes in nearshore sand deposits. This information can also be used to identify nearshore sand deposits for beach nourishment.

  • Bluff retreat and nearshore response to rising lake level: No studies have quantified the geomorphic evolution of the entire bluff, beach, and nearshore system during a period of lake level rise. Through frequent monitoring of coastal morphology and bathymetry insight will be gained into the co-evolution of these zones. Understanding how sediment is transported between these zones during storms and lake-level rise is imperative for being able to model coastal evolution and predict future coastal hazards.